Summa Prima 20 adding machine Designer (Person) Nizzoli, Marcello Manufacturer Olivetti Date 1960 - 1969 (circa)
Solar powered calculator promoting Barclays Bank Designer (Person) Unknown Manufacturer Unknown Manufactured for Barclays Bank Date 2004 (circa)
Addiator mechanical calculator Designer (Person) Unknown Manufacturer Kingson Date 1960 - 1979 (circa)
Petrous PRMC-1 calculator Designer (Person) Unknown Manufacturer Petrous Electronic Corp Date 1970 - 1999 (circa)